Mechanical DesignAbstract:A machine is a combination of mechanisms and other components whichtransforms, transmits. Examples are engines, turbines, vehicles, hoists, printing presses,washing machines, and movie cameras. Many of the principles and methods of designthat apply to machines also apply to manufactured articles that are not true machines. Theterm "mechanical design" is used in a broader sense than "machine design" to includetheir design. the motion and structural aspects and the provisions for retention andenclosure are considerations in mechanical design. Applications occur in the field ofmechanical engineering, and in other engineering fields as well, all of which requiremechanical devices, such as switches, cams, valves, vessels, and mixers.43508
Keywords: Mechanical Design ；Rules for Design ；Design Process
The Design ProcessDesigning starts with a need real.Existing apparatus may need improvements indurability, efficiency, weight, speed, or cost. New apparatus may be needed to perform afunction previously done by men, such as computation, assembly, or servicing. With theobjective wholly or partly.In the design preliminary stage, should allow to design the personnel fully to displaythe creativity, not each kind of restraint. Even if has had many impractical ideas, also canin the design early time, namely in front of the plan blueprint is corrected. Only then,only then does not send to stops up the innovation the mentality. Usually, must proposeseveral sets of design proposals, then perform the comparison. Has the possibility verymuch in the plan which finally designated, has used certain not in plan some ideas whichaccepts.When the general shape and a few dimensions of the several components becomeapparent, analysis can begin in earnest. The analysis will have as its objective satisfactoryor superior performance, plus safety and durability with minimum weight, and acompetitive cost. Optimum proportions and dimensions will be sought for each critically loaded section, together with a balance between the strengths of the several components.Materials and their treatment will be chosen. These important objectives can be attainedonly by analysis based upon the principles of mechanics, such as those of static forreaction forces and for the optimum utilization of friction; of dynamics for inertia,acceleration, and energy; of elasticity and strength of materials for stress and deflection;of physical behavior of materials; and of fluid mechanics for lubrication andhydrodynamic drives.
The analyses may be made by the same engineer who conceivedthe arrangement of mechanisms, or, in a large company, they may be made by a separateanalysis pision or research group. Design is a reiterative and cooperative process,whether done formally or informally, and the analyst can contribute to phases other thanhis own. Product design requires much research and development. Many Concepts of anidea must be studied, tried, and then either used or discarded. Although the content ofeach engineering problem is unique, the designers follow the similar process to solve theproblems.Product liability suits designers and forced in material selection, using the bestprogram. In the process of material, the most common problems for five (a) don'tunderstand or not use about the latest application materials to the best information, (b)failed to foresee and consider the reasonable use material may (such as possible,designers should further forecast and consider due to improper use products. In recentyears, many products liability in litigation, the use of products and hurt the plaintiffaccused manufacturer, and won the decision), (c) of the materials used all or some of thedata, data, especially when the uncertainty long-term performance data is so, (d) qualitycontrol method is not suitable and unproven, (e) by some completely incompetentpersons choose materials.Through to the above five questions analysis, may obtain these questions is does nothave the sufficient reason existence the conclusion. May for avoid these questions tothese questions research analyses the appearance indicating the direction. Although usesthe best choice of material method not to be able to avoid having the productresponsibility lawsuit, designs the personnel and the industry carries on the choice ofmaterial according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the materialnature, the characteristic and the processing method have comprehensive and the basicunderstanding.Finally, a design based upon function, and a prototype may be built. If its tests aresatisfactory, the initial design will undergo certain modifications that enable it to bemanufactured in quantity at a lower cost. During subsequent years of manufacture andservice, the design is likely to undergo changes as new ideas are conceived or as furtheranalyses based upon tests and experience indicate alterations. Sales appeal.Some Rules for DesignIn this section it is suggested that, applied with a creative attitude, analyses can lead toimportant improvements and to the conception and perfection of alternate, perhaps morefunctional, economical,and durable products.To stimulate creative thought, the following rules are suggested for the designer andanalyst. The first six rules are particularly applicable for the analyst. 机械设计英文文献及中文翻译:http://www.youerw.com/fanyi/lunwen_44385.html